Research Methods: A Comprehensive Study
Side 1: Chapter 4 – Research Design
Definition
The plan or blueprint for a study, outlining how data will be collected and analyzed.
Types
- Exploratory
- Descriptive
- Causal
Key Research Design Types
Exploratory Research
Conducted when little is known, aims to gain insights and clarify ideas.
Descriptive Research
Provides a detailed description of phenomena, without manipulation.
Causal Research
Establishes cause-and-effect relationships between variables.
Sampling Design
Probability Sampling
Every member of the population
Read MoreKey Concepts in Statistics: Data, Methods & Limitations
Limitations of Statistics
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Statistics does not deal with individuals:
- Statistics deals with an aggregate of facts and does not give specific recognition to individual items in a series.
- It deals with groups of individuals and indicates the characteristics of the whole group.
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Statistics does not deal directly with qualitative characteristics:
- Statistical methods can only be applied to numerically expressed data.
- A qualitative phenomenon must be converted into quantitative information before statistical
Understanding Statistical Variability and Distributions
Understanding Measures of Variability
Measures of variability indicate how much scores in a distribution vary, either from the mean or across the full extent of the distribution. It represents the spread of all the scores. Four measures of variability are discussed here: the range, the average mean deviation, the variance, and the standard deviation. These measures can reveal the consistency or similarity of the scores in a distribution and the extent to which the mean truly represents all of the
Read MoreUnderstanding Disease Frequency: Incidence, Prevalence, and Public Health Measures
Definition of Proportion
- A measure that states a count relative to the size of the group.
- A ratio in which the numerator is part of the denominator.
- May be expressed as a percentage.
Definition of Rate
- A ratio that consists of a numerator and a denominator and in which time forms part of the denominator.
- Contains the following elements:
- Disease frequency
- Unit size of population
- Time period during which an event occurs
Example of Rate Calculation
Definition of Prevalence
The number of existing cases of a disease
Read MoreCore Statistical Concepts and Applications
Linear Regression: Test Scores vs. Hours Studied
Consider the following linear regression equation: Test Scores = 45 + 5(Hours Studied)
- The Test Scores variable is the outcome variable. It is what the model is trying to predict.
- Hours Studied is the explanatory variable. It is used to explain or predict changes in the test scores.
- The slope coefficient associated with Hours Studied is 5. This indicates that for every additional hour spent studying, the model predicts an increase of 5 points in the test
Statistics Concepts: Observational Studies, Bias, and Inference
Statistics Concepts and Definitions
Ex. 1:
Observational study: No cause-effect; just associations. Five Number Summary = Min, Q1, Median, Q3, Max
Factors: Explanatory variable (x). Covariance: + or – relation but not strength
Block design: Individuals sharing the same characteristic are pooled.
SRS (Simple Random Sample); Stratified: Sample distinct groups separately then combine them. Sample survey: Cross-sectional; collect data of a population at one point in time.
Multistage: Using SRS within SRSs.
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